Answer:
5 hours.
Explanation:
Note that the clock "restarts" at 12, and flips from PM to AM (and vice versa).
In this case:
1st hour: 10:36 - 11:36pm
2nd hour: 11:36pm - 12:36am
3rd hour: 12:36am - 1:36am
4th hour: 1:36am - 2:36am
5th hour: 2:36am - 3:36am
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